Аннотация:Herein, we report on intermetallic iron germanide (Fe6Ge5) as a novel oxygen evolution reaction (OER) precatalyst with a Tafel slope of 32 mV dec1 and an overpotential of 272 mV at 100 mA cm2 in alkaline media. Furthermore, we uncover the in situ formation of a core–shell like structure that slowly collapses under OER conditions.